1. Field of the Invention
The present invention relates to a method which, in a process of manufacturing where high cleanliness is required to a ball/roller bearing, cleans an assembled ball/roller bearing before supplying oil or grease.
2. Description of the Related Art
Conventionally, as a method for cleaning a mechanical part, an ultrasonic cleaning method has been mainly used. In this ultrasonic cleaning method, for example, as shown in FIG. 14, a bearing 1 to be cleaned stored in a washing basket 50 is cleaned within a cleaning vessel 22 which includes an ultrasonic vibration plate 20 mounted on the bottom portion thereof and is filled with cleaning liquid 24.
Also, as a method for cleaning a ball/roller bearing, a patent is disclosed, for example, in Japanese Patent Unexamined Publication No. Hei. 11-138111 (JP-A-11-138111). In this cleaning method, a bearing to be cleaned is disposed on a rotary table where cleaning liquid is jetted onto the bearing from inside and outside as well as from above and below, thereby cleaning the bearing.
However, in the above-mentioned conventional ultrasonic cleaning method, due to the characteristics of ultrasonic waves, the ultrasonic waves are not able to effect the interior parts of the bearing to be cleaned, which results in insufficient cleaning. Especially, since the bearing to be cleaned is simply immersed in the cleaning liquid, it is difficult to completely remove dirt particles existing between the rolling bodies and retainer of the bearing to be cleaned.
Also, in the latter ultrasonic cleaning method, although the area of the bearing where the jetted cleaning liquid is applied can be cleaned, the cleaning liquid is splashed back from the portions of the bearing where it is applied, so that the portions of the bearing, where the jetted cleaning liquid cannot be applied directly, cannot be cleaned to a satisfactory degree. Therefore, it is difficult to completely remove dirt particles between the parts of the bearing to be cleaned, for example, between the rolling bodies and retainer of the bearing to be cleaned. Also, referring to an ultrasonic cleaning apparatus employed in enforcing the ultrasonic cleaning method, the structure thereof is complicated: that is, the ultrasonic cleaning apparatus is capable of cleaning a ball/roller bearing of a relatively large size but is not suitable to clean a ball/roller bearing of a small size.
The present invention aims at solving the drawbacks found in the above-mentioned conventional ball/roller bearing cleaning methods. Accordingly, an object of the invention is to provide a ball/roller bearing cleaning method and apparatus which enables highly effective cleaning even the portions of the bearing that are shaded from being cleaned with respect to the cleaning liquid, as well as cleaning the dirt particles caught between the parts of the bearing to be cleaned, that have been difficult to clean in the conventional ball/roller bearing cleaning methods.
In attaining the above object, according to a first aspect of the invention, a cleaning method is providedxe2x80x94for a bearing composed of an inner ring, an outer ring, rolling bodies and a retainerxe2x80x94using cleaning liquid, wherein the cleaning liquid is made to flow through the bearing to be cleaned from the axial direction of the bearing into spaces existing between the raceway surface of the inner ring and the raceway surface of the outer ring of the bearing to be cleaned and surrounding the rolling bodies and retainer.
According to the present ball/roller bearing cleaning method, the cleaning liquid is supplied from the axial direction of the bearing to be cleaned and into spaces which exist between the raceway surface of the inner ring and the raceway surface of the outer ring of the bearing to be cleaned and also surround the rolling bodies and retainer, whereby dirt particles caught in the part where the cleaning liquid cannot be applied directly, that is, dirt particles existing between the surfaces of the rolling bodies and retainer can be removed positively.
Also, according to a second aspect of the invention, in the ball/roller bearing cleaning method according to the first aspect of the invention, the cleaning liquid is supplied in a state where the inner or outer ring of the bearing to be cleaned is fixed and the other is rotatable, whereby, while driving or rotating the rotatable ring of the bearing to be cleaned, the cleaning liquid can be flowed through the bearing to be cleaned.
In this method, while the inner or outer ring of the bearing to be cleaned is fixed, the other ring is rotated, so that the rolling bodies and retainer are rotated. Especially, since the rolling bodies are capable of rotating about their own axes as well as around the axis of the bearing, dirt particles existing between the rolling bodies and retainer can be scraped out efficiently and, by supplying the cleaning liquid forcibly into between the inner ring raceway surface and outer ring raceway surface of the bearing to be cleaned, the thus scraped dirt particles can be discharged out of the bearing to be cleaned.
According to a third aspect of the invention, in the ball/roller bearing cleaning method according to the first aspect of the invention, preferably, the bearing to be cleaned may be immersed in a cleaning vessel filled with cleaning liquid and the cleaning liquid in the cleaning vessel may be vibrated by ultrasonic waves.
According to this cleaning method, by applying the ultrasonic vibrations to the cleaning liquid in the cleaning vessel, the ultrasonic waves can be radiated onto the rolling bodies and retainer included in the interior portion of the bearing to be cleaned, which can enhance the cleaning effect further.
And, according to a fourth aspect of the invention, in the ball/roller bearing cleaning method according to the first aspect of the invention, while one of the outer ring and inner ring of the bearing to be cleaned is fixed in the surface layer portion of the cleaning vessel filled with the cleaning liquid and the other ring is free to rotate, the cleaning liquid may be jetted onto the rolling bodies of the bearing to be cleaned from obliquely above the bearing to be cleaned in the circumferential direction thereof.
According to this method, in case where it is impossible to supply the cleaning liquid into the interior portion of the bearing to be cleaned, by jetting the cleaning liquid with high pressure while aiming at the rolling bodies of the bearing to be cleaned, the bearing to be cleaned can be cleaned while it is being rotated by the cleaning liquid.
And, according to a fifth aspect of the invention, in the ball/roller bearing cleaning method according to the first aspect of the invention, while one of the outer ring and inner ring of the bearing to be cleaned is fixed in the surface layer portion of the cleaning vessel filled with the cleaning liquid, the other ring may be driven or rotated.
According to this method, by rotating one of the outer ring and inner ring of the bearing to be cleaned using a motor or an air turbine, the bearing to be cleaned can be cleaned while rotating the same, which can enhance the cleaning effect.
And, according to a sixth aspect of the invention, in the ball/roller bearing cleaning method according to the first aspect of the invention, there may be employed a two-stage cleaning method: that is, after execution of a non-rotation cleaning step in which the bearing to be cleaned is cleaned by making the cleaning solution flow through the interior portion of the bearing to be cleaned without rotating the same (or in combination with ultrasonic cleaning), there may be executed a rotation cleaning step in which the bearing to be cleaned is cleaned while rotating the same.
This two-stage cleaning method is effective in the following case: that is, a large number of hard foreign substances are present in the interior portion of the bearing to be cleaned and thus, in case where the bearing to be cleaned is rotated in this state, there is a fear that the raceway surfaces of the inner ring and outer ring as well as the surfaces of the rolling bodies of the bearing to be cleaned can be damaged. Specifically, in the non-rotation cleaning step, the cleaning liquid is flowed through the bearing to be cleaned without rotating the same and, by radiating the ultrasonic waves onto the bearing to be cleaned from below, hard dirt particles existing in the interior portion of the bearing to be cleaned can be removed; and, after that, while rotating the bearing to be cleaned, it is cleaned. This can prevent the surfaces of the rolling bodies as well as the raceway surfaces of the inner ring and outer ring of the bearing to be cleaned from being damaged by the hard dirt particles.
Also, according to a seventh aspect of the invention, the ball/roller bearing cleaning method according to the first aspect of the invention can be accomplished by using a ball/roller cleaning apparatus for cleaning a bearing to be cleaned composed of an inner ring, an outer ring, rolling bodies and a retainer, the ball/roller cleaning apparatus comprising: raceway fixing unit for fixing the outer ring or inner ring of the bearing to be cleaned; a cleaning liquid supply passage for supplying the cleaning liquid to one side surface of the bearing to be cleaned; and, a cylindrical-shaped rotary die which has a diameter substantially equal to the diameter of the cleaning liquid supply passage and is rotatably supported within the cleaning liquid supply passage and also in the outer peripheral surface having spiral grooves.
According to this ball/roller bearing cleaning apparatus, when the cleaning liquid is supplied toward one surface of the bearing to be cleaned, the cleaning liquid is allowed to flow along the spiral grooves of the cylindrical-shaped rotary die to thereby rotate the cylindrical-shaped rotary die within the cleaning liquid supply passage and, due to a pumping action produced at that time by the spiral grooves, the pressure of the cleaning liquid is increased; and thus, the cleaning liquid having higher pressure than its initial pressure when it is supplied is jetted onto one surface of the bearing to be cleaned from the cylindrical-shaped rotary die. as a result of this, the cleaning liquid is forcibly made to flow from the axial direction of the bearing to be cleaned into spaces which are present between the inner ring raceway surface and outer ring raceway surface of the bearing to be cleaned and surround the rolling bodies and retainer, so that dirt particles existing between the rolling bodies and retainer can be scraped out therefrom and also can be then discharged out of the bearing to be cleaned.
Also, according to an eighth aspect of the invention, in the ball/roller bearing cleaning apparatus according to the seventh aspect of the invention, instead of the cylindrical-shaped rotary die, there can also be used a conical-shaped rotary die in which its diameter on the upstream side, where the cleaning liquid flows, is reduced, and the cleaning liquid supply passage can also be narrowed along the outside diameter of the conical-shaped rotary die.
According to this structure, in a case where the pressure of the cleaning liquid is increased and thus the force of the cleaning liquid to push the bearing to be cleaned in the axial direction thereof is strengthened, interference with the rotation of the outer and inner rings can be controlled, which makes it possible to carry out a smooth cleaning operation.
And, according to a ninth aspect of the invention, the ball/roller bearing cleaning apparatus according to the seventh aspect of the invention, preferably, may comprise a cleaning vessel filled with the cleaning liquid and an ultrasonically vibrating unit for applying ultrasonic vibrations to the cleaning liquid within the cleaning vessel.
According to this structure, since the ultrasonic waves can be radiated onto the inner ring, rolling bodies and retainer of the bearing to be cleaned, the whole interior portion of the bearing to be cleaned can be cleaned, thereby enhancing the cleaning effect.
Also, according to a tenth aspect of the invention, the ball/roller bearing cleaning apparatus according to the seventh aspect of the invention may also comprise a cleaning liquid jetting unit for jetting the cleaning liquid from obliquely above the bearing to be cleaned in the circumferential direction toward one side surface of the bearing to be cleaned, while the inner ring or outer ring of the bearing to be cleaned is rotatably supported on the surface layer portion of the cleaning vessel.
According to this structure, in a case where the cleaning liquid cannot be forcibly supplied into the interior portion of the bearing to be cleaned, by jetting the cleaning liquid from obliquely above the bearing to be cleaned from the cleaning liquid jetting unit onto the rolling bodies of the bearing to be cleaned, the bearing to be cleaned can be cleaned while rotating the same, which can enhance the cleaning effect.
And, according to an eleventh aspect of the invention, the ball/roller bearing cleaning apparatus according to the tenth aspect of the invention may also comprise, instead of the cleaning liquid jetting unit, raceway rotating unit for driving or rotating the inner ring or outer ring of the bearing to be cleaned which is free to rotate.
According to this structure, in a case where the cleaning liquid cannot be forcibly supplied into the interior portion of the bearing to be cleaned, by rotating the freely rotatable inner ring or outer ring of the bearing to be cleaned using a motor or an air turbine, the bearing to be cleaned can be cleaned while rotating the same, which can enhance the cleaning effect.